Lightning Mapping: Techniques, Challenges, and Opportunities

Abstract

Despite the significant progress in the understanding of the phenomenon of lightning and the physics behind it, locating and mapping its occurrence remain a challenge. Such localization and mapping of very high frequency (VHF) lightning radiation sources provide a foundation for the subsequent research on predicting lightning, saving lives, and protecting valuable assets. A major technical challenge in attempting to map the sources of lightning is mapping accuracy. The three common electromagnetic radio frequencybased lightning locating techniques are magnetic direction finder, time of arrival, and interferometer (ITF). Understanding these approaches requires critically reviewing previous attempts. The performance and reliability of each method are evaluated on the basis of the mapping accuracy obtained from lightning data from different sources. In this work, we review various methods for lightning mapping. We study the approaches, describe their techniques, analyze their merits and demerits, classify them, and derive few opportunities for further research. We find that the ITF system is the most effective method and that its performance may be improved further. One approach is to improve how lightning signals are preprocessed and how noise is filtered. Signal processing can also be utilized to improve mapping accuracy by introducing methods such as wavelet transform in place of conventional cross-correlation approaches. INDEX TERMS interferometer, lightning mapping, magnetic direction finder, time of arrival.

Lightning Detection and Imaging Based on VHF Radar Interferometry

“…With the configuration of closely spaced antennas, the phase difference of incident electromagnetic pulses between neighboring array units can be utilized to determine the azimuth and elevation angles of the target [4,50].…”

“…Lightning is an electrical discharge naturally occurring between charge regions of opposite polarities inside thunderclouds or between clouds and the ground, accompanying electromagnetic radiations over a wide range of frequencies during the formation of hot ionized plasma channels and visible luminous flashes [1,2]. To protect human life and assets from damage caused by the massive amount of energy released by lightning, lightning detection and localization methods and studies of lightning characteristics are of great significance [2][3][4][5].…”

“…Passive sferic detection systems employ networks of radiation-field sensors to detect and locate the lightning, which measure electromagnetic radiation fields emitted during multistage processes of lightning discharges in broadband frequency ranges from very-low frequency (VLF) through ultra-high frequency (UHF) [4,14]. Very-high-frequency (VHF) and VLF/low-frequency (LF) systems are distinguished based on the different frequency ranges of operation, pulse rates, and amplitudes in the RF spectrum [4]. In the VHF band, lightning mapping systems are commonly carried out using the interferometry (ITF) and time of arrival (TOA) technique or time difference of arrival technique (TDOA) [15][16][17][18][19][20][21][22][23].…”

“…The 3D structure of lightning channels can be obtained using two separated broadband interferometers or by combining other detection methods such as HSV and acoustic arrays [9,24]. However, the line-of-sight propagation of VHF radiation sets limits on the detection range of VHF systems [4]. In VLF detection, radiated pulses can propagate along the surface of earth or in the earth-ionosphere waveguide which can be utilized to locate lightning channels from a long distance [5,14,[25][26][27].…”

Azimuth and elevation factors correction for single station lightning electromagnetic field sensor

“…Based on the time difference between the detected electric signals by the broadband antenna and the acoustic signals, the lightning strike could be calculated. Additionally, based on (Alammari et al, 2020) findings, observation of VHF is the most common frequency band used in mapping lightning events. Based on that measurement, it could provide more comprehensive frequency components and accurate mapping compared to other frequency bands.…”